478 APPENDIX. 



dantly, in the coral-and shell limestones of the coal-formation ; 

 and that hitherto no remains of undoubted fossil saurian animals 

 had been met with in Scotland ; the large crocodile-like teeth 

 discovered in the coal-formation, in the year 1793, by the late 

 Rev. D, Ure, and figured by him in his History of Rutherglen 

 and Kilbride, and since, in 1834, by Dr Hibbert, at Burdiehouse, 

 near Edinburgh, belonging probably to an extinct tribe of fishes. 

 The sauroidal character of some of these fossils has elicited the 

 following remarks from Professor Agassiz : — 



" It is in the series of deposits inferior to the Lias that we be- 

 gin to find the largest of those monstrous Sauroid fishes, whose 

 osteology reminds us in many respects of the skeletons of saurian 

 animals, viz. by the closer sutures of the bones of the head, by 

 the large longitudinally striped conical teeth, and by the manner 

 in which the spinous epiphyses are articulated with the bodies 

 of the vertebrae, and the sides at the extremity of the transverse 

 epiphyses. The analogy which exists between these fishes and 

 saurian animals, is not confined to the skeleton alone ; for in one 

 of the two recent genera I have found a very peculiar internal 

 organization of the soft parts, which renders the similarity greater 

 than it at first appeared. There is, in fact, in the Lepidosteus 

 osseus, a glottis like that of the sirens and the salamandrian 

 reptiles, a cellular swimming-bladder, with a trachea, like the 

 lung of an ophidian. Finally, their integuments have often an 

 appearance so similar to that of the crocodiles, that it is not 

 always easy to distinguish them. 



" The sraallness of the number of fishes found in transition- 

 rocks, prevents us as yet from assigning to them a particular 

 character.* Nevertheless, the species in the collection of Mr 

 Murchison already indicate types which do not extend even to 

 the coal-formation. 



• The transition rocks mentioned by M. Agassiz, belong, we believe, 

 to the Silurian class of Murchison, the oldest Secondary of Professor 

 Jameson. 



